Which ankle control provides no movement?

• A. Free motion
• B. Solid ankle
• C. Limited motion
• D. DF assist

Answer: (B)

Understanding how ankle control changes movement helps you decide which orthosis to use. A solid ankle immobilization firmly locks the ankle joint, blocking plantarflexion, dorsiflexion, and sideways motion. That means there is no ankle movement at all, which is why this option provides no movement. In contrast, free-motion devices use an articulated ankle that allows the joint to move through its range. Limited-motion devices restrict some planes of motion, reducing movement but not eliminating it. Dorsiflexion-assist devices include a mechanism that actively helps bring the foot into dorsiflexion during swing, so there is movement and assistance rather than complete immobilization. So the device that provides no movement is the solid ankle option.